Water soluble saline aqueous dispersion of copolymers based on cationic monomers, method for making same and uses thereof

ABSTRACT

The invention concerns a water soluble saline dispersion of a copolymer obtained from a composition of water soluble monomers, comprising for 100 mole parts, 0.5 to 65 mole parts of at least a compound (1) and 0.5 to 95 mole parts of at least a monomer (II) and/or diethylaminoethyl (meth)acrylate quaternized with dimethyl sulphate wherein R 1 ═H or —CH 3 ; R 2 ═—CH 3 ; —C 2 H 5 ; —C 3 H 7  or —C 4 H 9 ; and compound (I) is optionally quaternized on one of the nitrogen atoms, which is symbolised by the fact that the R 3 , X −  and  +  associated with said nitrogen is between square brackets; when compound (I) is quaternized on a single nitrogen, R 3  and X −  represent the following: (1) R 3 ═—CH 3  or CH 2 C 6 H 5 ; and X − ═Cl −  or CH 3 OSO − ; or (2) R 3 ═—(CH 2 ) p CH 3  with p an integer from 3 to 11; and X − ═Br or I − ; when compound (I) is quaternized on both nitrogens, both X −  can be identical or different and the both R 3 , can be identical or different, in which case (3) R 3 ═—CH 2 —C 6 —H 5 ; and X − ═Cl − ; and (4) R 3 ═—(CH 2 ) p CH 3  with p an integer from 3 to 11; and X − ═Br or I − ; (5) among the compounds (I) quaternized on both nitrogens and having two different R 3 , if one of the R 3 ═CH 3 , C 2 H 5 , or C 3 H 7 ; and X − ═Cl −  of CH 3 OSO 3   − ; and the other ═—CH 2 C 6 H 5 , the associated X −  representing Cl − , or represents —(CH 2 ) p CH 3  with p an integer from 3 to 11, The associated X −  representing Br or I − ; R 8 ═H or CH 3 ; A 1 =O or NH; B 1 ═—CH 2 —CH 2 —or —CH 2 —CH 2 —CH 2 — or —CH 2 —CHOH—CH 2 —; R 9  and R 10 ═—CH 3 , —CH 2 —CH 3 ; R 11 ═—(CH 2 ) o —CH 3 (o=3 to 9) or benzyl; X − =monovalent ion.

[0001] The present invention relates to saline aqueous dispersions ofnovel water-soluble (co)polymers based on novel cationic monomers, tothe preparation of these dispersions and to their applications.

[0002] Some of these cationic monomers are novel, their synthesisforming the subject matter of a French patent application filed today onbehalf of the Applicant Company and having the title “Novel monomerscomprising quaternary amino groups, their process of manufacture and thenovel (co)polymers obtained from these novel monomers”. This novelmanufacturing process also applies to known monomers, in accordance witha patent application also filed today on behalf of the ApplicantCompany.

[0003] These novel cationic monomers make it possible to obtainwater-soluble (co)polymers which are insoluble in an aqueous solution ofinorganic salts but which are soluble by simple dilution with water.This property of the (co)polymers is thus taken advantage of ingenerating, by precipitation, in the course of polymerization in asaline aqueous medium, particles of (co)polymers which are stabilized bya second (co)polymer, which for its part is soluble in the medium andacts as dispersant. The aqueous dispersions of water-soluble(co)polymers thus obtained, which form the subject matter of the presentinvention, are used in various applications, which applications alsoform the subject matter of the present invention.

[0004] Water-soluble polymers are used for various applications and inparticular as flocculants for the treatment of municipal, waste andindustrial water, the dehydration of the sludges generated, asthickeners and flow treatment agents. It is well known that aqueoussystems of such water-soluble polymers with a high solids content aregelatinous and exhibit very high viscosities, which make them difficultto handle and to store. The problem posed to a person skilled in the artis the production of such aqueous systems but ones having both a highsolids content and a low viscosity.

[0005] Conventional processes for the synthesis of these polymerscomprise solution, reverse suspension and reverse emulsionpolymerization. Solution polymerization and reverse suspensionpolymerization result in products in the powder state which exhibit thedisadvantage of generating dust when used, of dissolving with difficultyin water and of not being able to form aqueous solutions of polymerswith a high concentration which can be easily handled. In addition tothis inconvenient implementation, which is specific to the pulverulentstate of the product, these two processes are disadvantageous in termsof production efficiency, first because of the low concentration ofmonomer used during the polymerization and, secondly, because of thedrying and/or milling stage, leading to an increase in the cycle timeand an additional energy consumption cost. The reverse emulsion process,which has been known for about two decades, for its part results in aproduct having a contaminating organic solvent.

[0006] To overcome these disadvantages, a novel polymerization techniquehas been developed which results in aqueous dispersions of water-solublepolymers, the novel feature of which is based on the presentation, thatis to say are devoid of contaminating solvent, do not generate dust, arerapidly dissolved in water, have a low viscosity at a high level ofpolymer and are ready to use. On the other hand, this technologyrequires the development of polymer dispersants suited to the stabilityof the polymer dispersed in a saline or nonsaline medium.

[0007] Some authors have prepared cationic or nonionic water-solublepolymers by polymerization of water-soluble monomers in the presence ofa polymer dispersant of low mass. European patent EP-B-170 394 disclosesa dispersion of particles of polymer gel with a size of greater than 20μm in a solution of poly(sodium acrylic) or poly(diallyldimethylammoniumchloride) dispersant. However, this product exhibits the disadvantage ofhaving a high viscosity after a long period of storage, it beingpossible for the viscosity to be reduced only after shearing orstirring.

[0008] European patent applications EP-A-183 466 and EP-A-525 751,United States patents U.S. Pat. Nos. 4,929,655 and 5,006,590, andEuropean patent application EP-A-657 478 provide for the case ofprecipitating polymerization in a saline medium of water-solublemonomers, the polymer of which precipitates in the form of particles andthen is dispersed by means of stirring and is stabilized by polymerdispersants of low mass, which for their part are soluble in a salinemedium. Furthermore, these particles are difficult to stabilize becauseof their large size (2-50 μm).

[0009] The problem which is consequently posed to a person skilled inthe art comprises:

[0010] (1) first, the development of polymer dispersants which aresoluble in a saline aqueous medium and which provide for good stabilityof the particles; and

[0011] (2) secondly, the development of water-soluble comonomers whichmake possible the manufacture of copolymers which are insoluble in anaqueous solution of salts, to make possible, by precipitation, theformation of the particles and, consequently, the “water/water emulsion”polymer dispersion.

[0012] As regards the dispersant, two approaches can be envisaged toachieve this objective of stabilization: first, by viscosifying thecontinuous phase using the associative effects contributed by thedispersant, to prevent the sedimentation of the particles, and,secondly, by promoting effective adsorption of the dispersant at thesurface of the particles for better effectiveness as protective colloid,to prevent the coalescence of the particles. In the latter case, thehydrophobic units present in the structure of the dispersant cancontribute strongly thereto. These dispersants have to have low masses,to provide for their solubility in a saline aqueous medium, and musthave cationic functional groups necessary for the flocculation. Typicaldispersants of these polymerizations are poly(diallyldimethylammoniumchloride) or the diallyldimethylammoniumchloride/(meth)acryloyloxyethyldimethylhexadecylammonium chloridecopolymer (cf. European patent application EP-A-657 478). In the lattercase, it is disclosed that the associative nature can be provided by thealkyl chains of the (meth)acryloyloxyethyldimethylhexadecylammoniumchloride. The synthesis of this dispersant is carried out in an aqueousmedium, thus making possible only the use of the second comonomer, whichadmittedly is less hydrophilic than diallyldimethylammonium chloride,but has to be water-soluble. This point places a considerable limitationon the hydrophobic nature of these dispersing copolymers. It isimportant to specify that an increase in the hydrophobic nature shouldmake it possible to obtain a dispersion of improved fluidity.

[0013] As regards the precipitated polymer to be stabilized, cationic oramphoteric copolymers are obtained by polymerizing a mixture ofwater-soluble monomers in the presence of dispersant, of water and ofsalts. As the copolymer is insoluble in a saline aqueous medium, polymerparticles are formed by precipitation because of the reduction in theelectrostatic repulsions of the polyelectrolyte of high molar mass. Thetypical monomer mixture for this type of polymerization is composed of(meth)acrylamide, of (meth)acryloxyethyldimethyltrimethylammoniumchloride and (meth)acryloxyethyldimethyldimethylbenzylammonium chloride(United States patent U.S. Pat. No. 4,929,655). The latter plays animportant role in the precipitation of the cationic polymer formedduring synthesis and in the formation of particles. United States patentU.S. Pat. No. 5,587,415 shows that it is possible to dispense with thismonomer by substituting it by another equivalent in which the benzylgroup is replaced by a sufficiently hydrophobic C₄₋₁₀ alkyl chain.Likewise, United States patent U.S. Pat. No. 5,614,602 shows that thesame results can be achieved by partially substituting the(meth)acrylamide by an N-alkylacrylamide or by an N,N-dialkylacrylamide.European patent application EP-A-0 717 056 claims dispersions ofamphoteric water-soluble polymers based on cationic monomers, including(meth)acryloxyethyldimethyldimethylbenzylammonium chloride, and anionicmonomers (acrylic acid), which dispersions are synthesized in thepresence of dispersant.

[0014] The patent documents JP-A-61 123 610, EP-A-183 466 and U.S. Pat.No. 5,006,590 disclose a process for the preparation of a saline aqueousdispersion of water-soluble polymer based on at least 5 mol % ofacryloxyethyldimethylbenzylammonium chloride (ADAMQUAT BZ). Europeanpatent application EP-A-0 525 751 relates to monomers of generalformula:

[0015] with o an integer from 3 to 9 and X⁻=monovalent anion which canbe Cl⁻, Br⁻ or I⁻, including ADAMQUAT C10, the monomer corresponding too=9, which, used in a proportion of at least 5 mol %, makes it possibleto obtain saline aqueous dispersions. United States patent U.S. Pat. No.5,696,228 provides for the use of diethylaminoethyl acrylate quaternizedby dimethyl sulfate:

[0016] (ADAE DMS)

[0017] (between 5 and 55 mol %) in combination with 0 to 35 mol % ofADAMQUAT BZ or of ADAMQUAT MC (acryloxyethyltrimethylammonium chloride)for the preparation of saline aqueous dispersions.

[0018] The Applicant Company has now discovered cationic monomers whichmake possible the preparation of water-soluble polymers which areinsoluble in an aqueous solution of inorganic salts but which aresoluble by simple dilution with water. It has thus developed a processfor the preparation of novel aqueous dispersions of water-solublepolymers, which dispersions are stabilized by a polymer dispersant,these aqueous dispersions meeting the set objectives of exhibiting goodfluidity and good stability on storage.

[0019] The Applicant Company has shown that copolymers obtained bycoupling the abovementioned monomers (of the S-ADAMQUAT 2BZ family,which will be described in more detail below) with the monomers of theADAMQUAT BZ family (which will also be described in more detail below)make it possible, first, to prepare fluid aqueous dispersions by using amolar level of the monomers of the ADAMQUAT BZ family generally of lessthan 5% and, secondly, to improve the process and fluidity of thedispersions of polymers having a level of these monomers of the ADAMQUATBZ family which is greater than 5%.

[0020] A first subject matter of the present invention is therefore asaline aqueous dispersion of a water-soluble copolymer obtained from amonomer compositions comprising, per 100 parts by moles:

[0021] (1) from 0.10 to 65 parts by moles of at least one compound offormula (I):

[0022] in which:

[0023] R¹ represents H or —CH₃;

[0024] R² represents —CH₃; —C₂H₅; —C₃H₇ or —C₄H₉; and

[0025] the compound (I) is optionally quaternized on one of thenitrogens, which is symbolized by the fact that the R³, X⁻ and ⁺entities associated with this nitrogen are between square brackets;

[0026] when the compound (I) is quaternized on just one nitrogen, R³ andX⁻ have the following meanings:

[0027] (1) R³ represents —CH₂—C₆H₅; and X⁻ represents Cl⁻ or CH₃OSO₃—;or

[0028] (2) R³ represents —(CH₂)_(p)CH₃ with p an integer from 3 to 11;and X⁻ represents Br⁻ or I⁻;

[0029] when the compound (I) is quaternized on both nitrogens, the twoX⁻ entities can be identical or different and the two R³ entities can beidentical or different, in which case:

[0030] (3) R³ represents —CH₂—C₆H₅; and X⁻ represents Cl⁻; or

[0031] (4) R³ represents —(CH₂)_(p)CH₃ with p an integer from 3 to 11;and X⁻ represents Br⁻ or I⁻;

[0032] (5) among the compounds (I) quaternized on both nitrogens andhaving the two R³ entities different, if one of the R³ entitiesrepresents —CH₃, —C₂H₅ or —C₃H₇; and X⁻ represents Cl⁻ or CH₃OSO₃—, theother represents —CH₂C₆H₅, the associated x representing Cl⁻, orrepresents —(CH₂)_(p)CH₃ with p an integer from 3 to 11, the associatedX⁻ representing Br⁻ or I⁻;

[0033] (2) from 0.5 to 95 parts by moles of at least one monomer chosenfrom:

[0034] (2a) those of the formula (II):

[0035] in which:

[0036] R⁸ represents H or —CH₃;

[0037] A¹ represents —O— or —NH—;

[0038] B¹ represents —CH₂—CH₂—, —CH₂—CH₂—CH₂— or —CH₂—CHOH—CH₂—;

[0039] R⁹ and R¹⁰ each represent —CH₃ or —CH₂CH₃;

[0040] R¹¹ represents —(CH₂)_(o)—CH₃, with o an integer from 3 to 9, or

[0041]  and

[0042] —X¹⁻ represents a monovalent ion, such as Cl⁻, SCN⁻, CH₃SO₃ ⁻ andBr⁻; and

[0043] (2b) those of formula (III):

[0044] in which:

[0045] R¹² represents H or —CH₃;

[0046] (3) from 0 to 95 parts by moles of at least one monomer offormula (IV):

[0047] in which:

[0048] R¹³ represents H or —CH₃;

[0049] R¹⁴ and R¹⁵, which are identical or different, each independentlyrepresent H or C₁₋₅ alkyl;

[0050] (4) from 0 to 95 parts by moles of at least one monomer offormula (V):

[0051] in which:

[0052] R¹⁶ represents H or —CH₃;

[0053] A² represents —O— or —NH—;

[0054] B² represents —CH₂CH₂—, —CH₂CH₂CH₂— or —CH₂CHOHCH₂—;

[0055] R¹⁷ and R¹⁸ each independently represent —CH₃ or —CH₂CH₃;

[0056] R¹⁹ represents H, —CH₃ or —CH₂CH₃;

[0057] X² ⁻ represents a monovalent anion, such as Cl⁻, SCN⁻, CH₃SO₃ ⁻and Br⁻;

[0058] (5) from 0 to 95 parts by moles of at least one monomer of theformula (VI):

[0059] in which:

[0060] R¹ represents H or —CH₃;

[0061] R² represents —CH₃; —C₂H₅ or —C₃H₇; and

[0062] the compound (IV) is optionally quaternized on one of thenitrogens, which is symbolized by the fact that the R³, X⁻ and ⁺entities associated with this nitrogen are between square brackets;

[0063] R³ represents —CH₃, —C₂H₅ or —C₃H₇; and

[0064] X⁻ represents Cl⁻ or CH₃OSO₃ ⁻; and

[0065] when the compound (VI) is quaternized on both nitrogens, the twoX⁻ entities can be identical or different and the two R³ entities can beidentical or different; and

[0066] (6) from 0 to 50 parts by moles of at least one anionic monomerchosen from carboxylic acids comprising ethylenic unsaturation, sulfonicacids comprising ethylenic unsaturation, sulfuric acids comprisingethylenic unsaturation and the derivatives of these acids (such as, forexample, the salts).

[0067] The preferred monomer of formula (I) is the compound of formula(Ia):

[0068] Mention may be made, as examples of monomers (2a), of ADAMQUAT BZand ADAMQUAT C10, the designations of which were indicated above.

[0069] Mention may be made, as examples of monomers (3), of acrylamide,N-methylacrylamide and N,N-dimethylacrylamide.

[0070] Mention may be made, as examples of monomers (4), of(meth)acryloxyethyltrimethylammonium halides (chlorides).

[0071] Mention may be made, as an example of monomer (5), of thecompound of formula (VIa):

[0072] Mention may be made, as examples of monomers (6), of(meth)acrylic acid and the acid 3-sulfopropyl (meth)-acrylate.

[0073] In accordance with a preferred embodiment of the dispersionsaccording to the invention, the latter comprise:

[0074] (A) from 10 to 50 parts by weight, in particular from 15 to 30parts by weight, of dispersed copolymer based on the composition of theabove-mentioned monomers (1) to (6);

[0075] (B) from 0.5 to 25 parts by weight, in particular from 1 to 10parts by weight, of at least one dispersing (co)polymer; and

[0076] (C) from 10 to 45 parts by weight, in particular from 21.5 to 34parts by weight, of at least one inorganic salt such that the aqueoussolution of said salt dissolves said dispersing copolymer withoutdissolving said dispersed copolymer formed during polymerization,

[0077] the remainder being composed of water.

[0078] The dispersing (co)polymer or (co)polymers (B) are chosen fromcationic, amphoteric or nonionic (co)polymers with a molar mass of lessthan 600 000, soluble or partially soluble in a saline aqueous medium.

[0079] The following may be indicated, by way of example:

[0080] poly(diallyldimethylammonium chloride);

[0081] poly(acryloxyethyltrimethylammonium chloride);

[0082] copolymers based on diallyldimethylammonium chloride or onacryloxyethyltrimethylammonium chloride;

[0083] styrene-maleic anhydride copolymers which are imidized andquaternized by an alkyl chloride or benzyl chloride or by an acid;

[0084] poly(acrylamidopropylpropyltrimethylammonium chloride);

[0085] polyacrylamide;

[0086] poly(vinyl alcohol); and

[0087] poly(ethylene oxide).

[0088] The preferred dispersants are:

[0089] cationic polymers based on styrene, onacryloxyethyltrimethylammonium chloride and on polyethoxy methacrylate,with or without a hydrophobic group, the latter being either thetriphenylstyryl group or an alkyl chain;

[0090] amphoteric polymers based on styrene, onacryloxyethyltrimethylammonium chloride, on methacrylic acid and onpolyethoxy methacrylate, with or without a hydrophobic group, the latterbeing either the triphenylstyryl group or an alkyl chain;

[0091] cationic polymers based on styrene, on diallyldimethylammoniumchloride and on polyethoxy methacrylate, with or without a hydrophobicgroup, the latter being either the triphenylstyryl group or an alkylchain; and

[0092] cationic polymers based on styrene, onacryloxyethyltrimethylammonium chloride and on alkyl (meth)acrylatecomprising a long C₁₂₋₃₀ chain, the polyethoxy methacrylate with atriphenylstyryl group being represented by the formula (VII):

[0093] with r an integer from 1 to 60.

[0094] The salt or salts (C) are inorganic salts, the aqueous solutionof which dissolves the dispersing polymers without dissolving thedispersed polymer formed during the polymerization. Representative saltsare ammonium sulfate, sodium sulfate, aluminum sulfate, sodium chloride,sodium dihydrogenphosphate and sodium hydrogenphosphate. Thesekosmotropic salts can be combined with a chaotropic salt, such as sodiumthiocyanate or ammonium thiocyanate.

[0095] The present invention also relates to a process for themanufacture of an aqueous dispersion as defined above, characterized inthat a radical polymerization in a saline aqueous medium of the monomeror monomers (1) to (6) as defined above is carried out in the presenceof at least one polymer dispersant (B) as defined above and of at leastone inorganic salt (C) as defined above.

[0096] The aqueous dispersion is prepared by using in particular:

[0097] from 10 to 50 parts by weight, in particular from 15 to 30 partsby weight, of the composition of the abovementioned water-solublemonomers (1) to (6);

[0098] from 0.5 to 25 parts by weight, in particular from 1 to 10 partsby weight, of the polymer dispersant or dispersants (B); and

[0099] from 10 to 45 parts by weight, in particular from 21.5 to 34parts by weight, of the salt or salts (C),

[0100] these parts being with respect to 100 parts by weight of thereaction mixture composed of water, the dispersing polymer or polymers(B), the salt or salts (C) and the composition of the monomers (1) to(6).

[0101] The salt or salts (C) can be added on two occasions. Thus, duringthe polymerization, 10 to 30 parts by weight of salt(s), preferably 16.5to 25 parts by weight, can be added and, in postaddition, 2 to 15 partsby weight of salt(s) can be added. It is also possible to add all thesalt or salts during the polymerization.

[0102] The polymerization can be initiated by various means, such asfree radical generators, for example peroxides, diazo compounds orpersulfates, or by irradiation. The preferred form according to theinvention is initiation by 2,2′-azobis(N,N′-dimethyleneisobutyramidine)dihydrochloride or 2,2′-azobis(2-aminopropane) hydrochloride. Theseinitiators can be combined with a decomposition accelerator. Thepolymerization temperature is between −40° C. and 160° C., preferablybeing from 30 to 95° C. The conversion is greater than 99%.

[0103] The present invention also relates to the use of the dispersionsof water-soluble copolymers as defined above or prepared by the processas defined above as flocculating agents for the treatment of wastewater; dehydrating agents; agents for retaining fibers and fillers inprocesses for the manufacture of paper; agents facilitating the cleaningof supports, such as textiles; agents for dispersing fillers; inhibitingagents for the transfer of pigments and dyes onto various supports, suchas textile; and thickeners.

[0104] The examples which will follow, given by way of indication, makepossible a better understanding of the invention. In these examples, theparts and percentages indicated are by weight, unless otherwiseindicated, and the following abbreviations were used:

[0105] ADAME: dimethylaminoethyl acrylate

[0106] ADAMQUAT MC: acryloxyethyltrimethylammonium chloride

[0107] ADAMQUAT BZ: acryloxyethyldimethylbenzylammonium chloride

[0108] S-ADAME: (2-dimethylamino-1-dimethylaminomethyl)-ethyl acrylate:

[0109] S-ADAMQUAT 2BZ: compound of the abovementioned formula (Ia)

[0110] SIPOMER SEM: polyethoxy methacrylate with a triphenylstyrylgroup, of formula:

[0111] AMA: methacrylic acid

[0112] ABAH: 2,2′-azobis(2-aminopropane) hydrochloride

[0113] VA-044: 2,2′-azobis(N,N′-dimethyleneisobutyramidine)dihydrochloride

EXAMPLE 1 Of Preparation

[0114] (a) Synthesis of S-ADAME

[0115] The following are charged to a 1 liter glass reactor:

[0116] 292 g of 1,3-bis(dimethylamino)-2-propanol;

[0117] 242 g of triethylamine; and

[0118] 0.373 g of phenothiazine, as stabilizer.

[0119] 226 g of acrylic anhydride are added to this stirred mixture over1 hour at ambient temperature while bubbling with air. The temperatureincreases to reach 50° C. After reacting for an additional 2 hours, themixture is cooled and 50 ml of water are added. After separating bysettling, an upper organic phase of 450 g is obtained and is distilledunder reduced pressure to isolate 250 g of the title compound (GC purity≧99%).

[0120] (b) Quaternization of S-ADAME to S-ADAMQUAT 2BZ

[0121] 44.2 g of the S-ADAME obtained in point (a), stabilized with 1500 ppm of hydroquinone methyl ether, and 150 g of CHCl₃ are charged toa 250 ml glass reactor. The mixture is brought to 50° C. with stirringand while bubbling with air. 55.9 g of benzyl chloride are added over 1hour. After reacting for 25 hours, the starting acrylate has disappearedand 33 g of water are added. An upper phase is separated by settling andis freed from the traces of CHCl₃ by stripping with air at 45° C. underreduced pressure (P=1.33×10⁴ Pa) (100 mmHg)). 115.2 g of aqueoussolution are thus obtained, which solution comprises 75% of quaternarycationic monomer having the expected structure, determined by ¹³C NMR.This monomer is known as S-ADAMQUAT 2BZ.

EXAMPLE 2 Preparation of a Dispersing Copolymer

[0122] The following are introduced with stirring into a 1 literreactor:

[0123] 703.3 parts of water;

[0124] 36.83 parts of styrene; and

[0125] 339.4 parts of an 80% aqueous ADAMQUAT MC solution;

[0126] 33.6 parts of a commercial aqueous solution composed of SIPOMERSEM, AMA and water, in the proportions of 60% of SIPOMER SEM, 20% of AMAand 20% of water.

[0127] The reactor is brought to 70° C. while flushing with nitrogen andwith stirring (150 rpm; anchor stirrer). When the temperature of thereaction medium has stabilized at 70° C., 0.2 part of ABAH issubsequently introduced. After reacting for 3 hours at 70° C., thetemperature of the reaction medium is brought to 80° C. and 0.2 part ofABAH is introduced. After heating for 2 hours at 80° C., the reactionmedium is cooled and a solution comprising 30.3% of water-solublecopolymer is recovered, the copolymer having the molar composition:

[0128] styrene/ADAMQUAT MC/SIPOMER SEM/AMA 19.23/76.25/0.67/3.84.

EXAMPLE 3 Preparation of an Aqueous Dispersion of Water-SolubleCopolymer, which Dispersion is Stabilized by the Dispersing Copolymer ofExample 2

[0129] The following are introduced, with stirring, into a 1 literreactor:

[0130] 130 parts of water;

[0131] 120 parts of the aqueous solution comprising 30.3% ofwater-soluble dispersing copolymer obtained in example 2;

[0132] 20.43 parts of an aqueous solution comprising 73.5% of S-ADAMQUAT2BZ;

[0133] 87.50 parts of 50% acrylamide in water;

[0134] 60.70 parts of an 80% aqueous ADAMQUAT MC solution;

[0135] 15.85 parts of an 80% aqueous ADAMQUAT BZ solution; and

[0136] 100 parts of ammonium sulfate.

[0137] The reactor is brought to 53° C. for 30 minutes while flushingwith nitrogen and 0.12 part of VA-044, diluted in 12 parts of water, isintroduced. The temperature is maintained at 53° C. for 2 hours. 0.048part of VA-044, diluted in 6 parts of water, is subsequently added andthe reaction is allowed to take place for an additional 30 minutes at53° C. The reactor is heated to a temperature of 60° C. and, after 2 h30, a postaddition of the following ingredients is carried out:

[0138] 32 parts of ammonium sulfate;

[0139] 0.6 part of ammonium thiocyanate; and

[0140] 6 parts of acetic acid.

[0141] After mixing for one hour, the reaction medium is cooled to 30°C. and the reactor is emptied.

[0142] A stable dispersion of acrylamide/ADAMQUAT BZ/S-ADAMQUAT2BZ/ADAMQUAT MC molar 65/4.95/3.5/26.55 copolymer is obtained, whichdispersion is stabilized by the copolymer dispersant of example 2 andhas a Brookfield viscosity of 1 200 mPa.s (1 200 cP) at 25° C.

EXAMPLE 4 Preparation of an Aqueous Dispersion of Water-SolubleCopolymer, which Dispersion is Stabilized by the Dispersing Copolymer ofExample 2

[0143] The following are introduced, with stirring, into a 1 literreactor:

[0144] 138 parts of water;

[0145] 120 parts of the aqueous solution comprising 30.3% ofwater-soluble dispersing copolymer obtained in example 2;

[0146] 17.57 parts of an aqueous solution comprising 73.5% of S-ADAMQUAT2BZ;

[0147] 88.38 parts of 50% acrylamide in water;

[0148] 62.70 parts of an 80% aqueous ADAMQUAT MC solution;

[0149] 15.85 parts of an 80% aqueous ADAMQUAT BZ solution; and

[0150] 100 parts of ammonium sulfate.

[0151] The reactor is brought to 53° C. for 30 minutes while flushingwith nitrogen and 0.12 part of VA-044, diluted in 12 parts of water, isintroduced. The temperature is maintained at 53° C. for 2 hours. 0.048part of VA-044, diluted in 6 parts of water, is subsequently added andthe reaction is allowed to take place for an additional 30 minutes at53° C. The reactor is heated to a temperature of 60° C. and, after 2 h30, a postaddition of the following ingredients is carried out:

[0152] 32 parts of ammonium sulfate;

[0153] 0.6 part of ammonium thiocyanate; and

[0154] 6 parts of acetic acid.

[0155] After mixing for one hour, the reaction medium is cooled to 30°C. and the reactor is emptied.

[0156] A stable dispersion of acrylamide/ADAMQUAT BZ/S-ADAMQUAT2BZ/ADAMQUAT MC molar 65/4.95/3/27 copolymer is obtained, whichdispersion is stabilized by the copolymer dispersant of example 2 andhas a Brookfield viscosity of 1 350 mPa.s (1 350 cP) at 25° C.

EXAMPLE 5 Preparation of an Aqueous Dispersion of Water-SolubleCopolymer, which Dispersion is Stabilized by the Dispersing Copolymer ofExample 2

[0157] The following are introduced, with stirring, into a 1 literreactor:

[0158] 138 parts of water;

[0159] 120 parts of the aqueous solution comprising 30.3% ofwater-soluble dispersing copolymer obtained in example 2;

[0160] 12.04 parts of an aqueous solution comprising 73.5% of S-ADAMQUAT2BZ;

[0161] 90.27 parts of 50% acrylamide in water;

[0162] 66.16 parts of an 80% aqueous ADAMQUAT MC solution;

[0163] 16.35 parts of an 80% aqueous ADAMQUAT BZ solution; and

[0164] 100 parts of ammonium sulfate.

[0165] The reactor is brought to 53° C. for 30 minutes while flushingwith nitrogen and 0.12 part of VA-044, diluted in 5 parts of water, isintroduced. The temperature is maintained at 53° C. for 2 hours. 0.048part of VA-044, diluted in 6 parts of water, is subsequently added andthe reaction is allowed to take place for an additional 30 minutes at53° C. The reactor is heated to a temperature of 60° C. and, after 2 h30, a postaddition of the following ingredients is subsequently carriedout:

[0166] 32 parts of ammonium sulfate;

[0167] 0.6 part of ammonium thiocyanate; and

[0168] 6 parts of acetic acid.

[0169] After mixing for one hour, the reaction medium is cooled to 30°C. and the reactor is emptied. A stable dispersion ofacrylamide/ADAMQUAT BZ/S-ADAMQUAT 2BZ/ADAMQUAT MC molar 65/4.95/2/27copolymer is obtained, which dispersion is stabilized by the copolymerdispersant of example 2 and has a Brookfield viscosity of 1 800 mPa.s (1800 cP) at 25° C.

EXAMPLE 6 (COMPARATIVE) Preparation of an Aqueous Dispersion ofWater-Soluble Copolymer Without S-ADAMQUAT 2BZ

[0170] The following are introduced, with stirring, into a 1 literreactor:

[0171] 138 parts of water;

[0172] 120 parts of the aqueous solution comprising 30.3% ofwater-soluble dispersing copolymer obtained in example 2;

[0173] 96.72 parts of 50% acrylamide in water;

[0174] 72.30 parts of an 80% aqueous ADAMQUAT MC solution;

[0175] 17.25 parts of an 80% aqueous ADAMQUAT BZ solution; and

[0176] 100 parts of ammonium sulfate.

[0177] The reactor is brought to 53° C. for 30 minutes while flushingwith nitrogen and 0.12 part of VA-044, diluted in 12 parts of water, isintroduced. The temperature is maintained at 53° C. for 2 hours. 0.048part of VA-044, diluted in 6 parts of water, is subsequently added andthe reaction is allowed to take place for an additional 30 minutes at53° C. The. reactor is heated to a temperature of 60° C. and, after 2 h30, a postaddition of the following ingredients is carried out:

[0178] 32 parts of ammonium sulfate;

[0179] 0.6 part of ammonium thiocyanate; and

[0180] 6 parts of acetic acid.

[0181] After mixing for one hour, the reaction medium is cooled to 30°C. and the reactor is emptied.

[0182] The product sets solid after polymerizing for 20 minutes and agel is obtained which is composed of acrylamide/ADAMQUAT BZ/ADAMQUAT MCmolar 66/4.95/29.05 copolymer and of the copolymer dispersant of example2 and which has a high viscosity, unmeasurable by the above device.

[0183] For a level of 4.95 mol % of ADAMQUAT BZ in the composition ofthe monomers to be polymerized, it is therefore impossible to obtain anaqueous polymer dispersion. The copolymer, which does not comprisesufficient cationic units of low hydrophilicity to make possible theprecipitation of the polymer, is converted into a highly viscous gel. Onthe other hand, the incorporation of a low level of S-ADAMQUAT 2BZ (2 to3.5 mol %) in the composition of the monomer, while retaining the levelof ADAMQUAT BZ at 4.95 mol %, renders the novel copolymer lesshydrophilic, thus promoting its precipitation and the production of afluid aqueous dispersion. Furthermore, the fluidity of the dispersion isimproved by increasing the level of S-ADAMQUAT 2BZ.

EXAMPLE 7 (COMPARATIVE) Preparation of a Dispersion of Water-SolublePolymer Without S-ADAMQUAT 2BZ

[0184] The following are introduced, with stirring, into a 1 literreactor:

[0185] 138 parts of water;

[0186] 120 parts of the aqueous solution comprising 30.3% ofwater-soluble dispersing copolymer obtained in example 2;

[0187] 96.0 parts of 50% acrylamide in water;

[0188] 62.53 parts of an 80% aqueous ADAMQUAT MC solution;

[0189] 27.47 parts of an 80% aqueous ADAMQUAT BZ solution; and

[0190] 100 parts of ammonium sulfate.

[0191] The reactor is brought to 53° C. for 30 minutes while flushingwith nitrogen and 0.12 part of VA-044, diluted in 12 parts of water, isintroduced. The temperature is maintained at 53° C. for 2 hours. 0.048part of VA-044, diluted in 6 parts of water, is subsequently added andthe reaction is allowed to take place for an additional 30 minutes at53° C. The reactor is heated to a temperature of 60° C. and, after 2 h30, a postaddition of the following ingredients is carried out:

[0192] 32 parts of ammonium sulfate;

[0193] 0.6 part of ammonium thiocyanate; and

[0194] 6 parts of acetic acid.

[0195] After mixing for one hour, the reaction medium is cooled to 30°C. and the reactor is emptied.

[0196] The product sets solid after polymerizing for 20 minutes and agel is obtained which is composed of acrylamide/ADAMQUAT BZ/ADAMQUAT MCmolar 66.5/8/26 copolymer and of the copolymer dispersant of example 2and which has a high viscosity, unmeasurable by the above device.

[0197] For a higher level of ADAMQUAT BZ (8 mol %) in the composition ofthe monomers to be polymerized, it is therefore impossible to obtain anaqueous polymer dispersion. The copolymer, which does not comprisesufficient cationic units of low hydrophilicity to make possible theprecipitation of the polymer, is converted into a highly viscous gel.

EXAMPLE 8 Preparation of an Aqueous Dispersion of Water-Soluble PolymerHaving 8 mol % of ADAMQUAT BZ Coupled with S-ADAMQUAT 2BZ, whichDispersion is Stabilized by the Dispersing Copolymer of Example 2

[0198] The following are introduced, with stirring, into a 1 literreactor:

[0199] 138 parts of water;

[0200] 120 parts of the aqueous solution comprising 30.3% ofwater-soluble dispersing copolymer obtained in example 2;

[0201] 11.74 parts of an aqueous solution comprising 73.5% of S-ADAMQUAT2BZ;

[0202] 88.57 parts of 50% acrylamide in water;

[0203] 57.86 parts of an 80% aqueous ADAMQUAT MC solution;

[0204] 25.93 parts of an 80% aqueous ADAMQUAT BZ solution; and

[0205] 100 parts of ammonium sulfate.

[0206] The reactor is brought to 53° C. for 30 minutes while flushingwith nitrogen and 0.12 part of VA-044, diluted in 12 parts of water, isintroduced. The temperature is maintained at 53° C. for 2 hours. 0.048part of VA-044, diluted in 6 parts of water, is subsequently added andthe reaction is allowed to take place for an additional 30 minutes at53° C. The reactor is heated to a temperature of 60° C. and, after 2 h30, a postaddition of the following ingredients is carried out:

[0207] 32 parts of ammonium sulfate;

[0208] 0.6 part of ammonium thiocyanate; and

[0209] 6 parts of acetic acid.

[0210] After mixing for one hour, the reaction medium is cooled to 30°C. and the reactor is emptied.

[0211] A stable dispersion of acrylamide/ADAMQUAT BZ/S-ADAMQUAT2BZ/ADAMQUAT MC molar 65/8/2/25 copolymer is obtained, which dispersionis stabilized by the copolymer dispersant of example 2 and has aBrookfield viscosity of 1 050 mPa.s (1 050 cP) at 25° C.

EXAMPLE 9 Preparation of an Aqueous Dispersion of Water-SolubleCopolymer Having 8 mol % of ADAMQUAT BZ Coupled with S-ADAMQUAT 2BZ,which Dispersion is Stabilized by the Dispersing Copolymer of Example 2

[0212] The following are introduced, with stirring, into a 1 literreactor:

[0213] 138 parts of water;

[0214] 120 parts of the aqueous solution comprising 30.3% ofwater-soluble dispersing copolymer obtained in example 2;

[0215] 17.25 parts of an aqueous solution comprising 73.5% of S-ADAMQUAT2BZ;

[0216] 86.77 parts of 50% acrylamide in water;

[0217] 54.41 parts of an 80% aqueous ADAMQUAT MC solution;

[0218] 25.40 parts of an 80% aqueous ADAMQUAT BZ solution; and

[0219] 100 parts of ammonium sulfate.

[0220] The reactor is brought to 53° C. for 30 minutes while flushingwith nitrogen and 0.12 part of VA-044, diluted in 12 parts of water, isintroduced. The temperature is maintained at 53° C. for 2 hours. 0.048part of VA-044, diluted in 6 parts of water, is subsequently added andthe reaction is allowed to take place for an additional 30 minutes at53° C. The reactor is heated to a temperature of 60° C. and, after 2 h30, a postaddition of the following ingredients is carried out:

[0221] 32 parts of ammonium sulfate;

[0222] 0.6 part of ammonium thiocyanate; and

[0223] 6 parts of acetic acid.

[0224] After mixing for one hour, the reaction medium is cooled to 30°C. and the reactor is emptied.

[0225] A stable dispersion of acrylamide/ADAMQUAT BZ/S-ADAMQUAT2BZ/ADAMQUAT MC molar 65/8/3/24 copolymer is obtained, which dispersionis stabilized by the copolymer dispersant of example 2 and has aBrookfield viscosity of 800 mPa.s (800 cP) at 25° C.

[0226] For a higher level of ADAMQUAT BZ (8 mol %) in the composition ofthe monomers to be polymerized, the incorporation of S-ADAMQUAT 2BZexhibits the advantage, first, of improving the fluidity of thedispersion and, secondly, of preventing a highly viscous product frombeing obtained during polymerization.

1. A saline aqueous dispersion of a water-soluble copolymer obtainedfrom a monomer compositions comprising, per 100 parts by moles: (1) from0.10 to 65 parts by moles of at least one compound of formula (I):

in which: R¹ represents H or —CH₃; R² represents —CH₃; —C₂H₅; —C₃H₇ or—C₄H₉; and the compound (I) is optionally quaternized on one of thenitrogens, which is symbolized by the fact that the R³, X⁻ and ⁺entities associated with this nitrogen are between square brackets; whenthe compound (I) is quaternized on just one nitrogen, R³ and X⁻ have thefollowing meanings: (1) R³ represents —CH₂C₆H₅; and X⁻ represents Cl⁻ orCH₃OSO₃ ⁻; or (2) R³ represents —(CH₂)_(p)CH₃ with p an integer from 3to 11; and X⁻ represents Br⁻ or I⁻; when the compound (I) is quaternizedon both nitrogens, the two X⁻ entities can be identical or different andthe two R³ entities can be identical or different, in which case: (3) R³represents —CH₂—C₆H₅; and X⁻ represents Cl⁻; or (4) R³ represents—(CH₂)_(p)CH₃ with p an integer from 3 to 11; and X⁻ represents Br⁻ orI⁻; (5) among the compounds (I) quaternized on both nitrogens and havingthe two R³ entities different, if one of the R³ entities represents—CH₃, —C₂H₅ or —C₃H₇; and X⁻ represents Cl⁻ or CH₃OSO₃ ⁻, the otherrepresents —CH₂C₆H₅, the associated X⁻ representing Cl⁻, or represents—(CH₂)_(p)CH₃ with p an integer from 3 to 11, the associated X⁻representing Br⁻ or I⁻; (2) from 0.5 to 95 parts by moles of at leastone monomer chosen from: (2a) those of the formula (II):

in which: R⁸ represents H or —CH₃; A¹ represents —O— or —NH—; B¹represents —CH₂—CH₂—, —CH₂—CH₂—CH₂— or —CH₂—CHOH—CH₂—; R⁹ and R¹⁰ eachrepresent —CH₃ or —CH₂CH₃; R¹¹ represents —(CH₂)_(o)—CH₃, with o aninteger from 3 to 9, or

 and X¹⁻ represents a monovalent ion; and (2b) those of formula (III):

in which: R¹² represents H or —CH₃; (3) from 0 to 95 parts by moles ofat least one monomer of formula (IV):

in which: R represents H or —CH₃; R¹⁴ and R¹⁵, which are identical ordifferent, each independently represent H or C₁₋₅ alkyl; (4) from 0 to95 parts by moles of at least one monomer of formula (V):

in which: R¹⁶ represents H or —CH₃; A² represents —O— or —NH—; B²represents —CH₂CH₂—, —CH₂CH₂CH₂— or —CH₂CHOHCH₂—; R¹⁷ and R¹⁸ eachindependently represent —CH₃ or —CH₂CH₃; R¹⁹ represents H, —CH₃ or—CH₂CH₃; X²⁻ represents a monovalent anion; (5) from 0 to 95 parts bymoles of at least one monomer of the formula (VI):

in which: R¹ represents H or —CH₃; R² represents —CH₃; —C₂H₅ or —C₃H₇;and the compound (IV) is optionally quaternized on one of the nitrogens,which is symbolized by the fact that the R³, X⁻ and ⁺ entitiesassociated with this nitrogen are between square brackets; R³ represents—CH₃, —C₂H₅ or —C₃H₇; and X⁻ represents Cl⁻ or CH₃OSO₃—; and when thecompound (VI) is quaternized on both nitrogens, the two X⁻ entities canbe identical or different and the two R³ entities can be identical ordifferent; and (6) from 0 to 50 parts by moles of at least one anionicmonomer chosen from carboxylic acids comprising ethylenic unsaturation,sulfonic acids comprising ethylenic unsaturation, sulfuric acidscomprising ethylenic unsaturation and the derivatives of these acids. 2.The aqueous dispersion as claimed in claim 1, characterized in that thecompound (I) is that represented by the formula (Ia):


3. The aqueous dispersion as claimed in either of claims 1 and 2,characterized in that it comprises, per 100 parts by weight: (A) from 10to 50 parts by weight of dispersed copolymer based on the composition ofthe monomers (1) to (6) as defined in either of claims 1 and 2; (B) from0.5 to 25 parts by weight of at least one dispersing (co)polymer; and(C) from 10 to 45 parts by weight of at least one inorganic salt suchthat the aqueous solution of said salt dissolves the dispersing(co)polymer without dissolving the dispersed copolymer formed duringpolymerization, the remainder being composed of water.
 4. The aqueousdispersion as claimed in claim 3, characterized in that it comprises:(A) from 15 to 30 parts by weight of the dispersed copolymer; (B) from 1to 10 parts by weight of the dispersing (co)polymer or (co)polymers; and(C) from 21.5 to 34 parts by weight of the inorganic salt or salts, theremainder being composed of water.
 5. The dispersion as claimed ineither of claims 3 and 4, characterized in that the dispersing(co)polymer or (co)polymers (B) are chosen from cationic, amphoteric ornonionic (co)polymers with a molecular mass of less than 600 000,soluble or partially soluble in a saline aqueous medium.
 6. Thedispersion as claimed in claim 5, characterized in that the dispersing(co)polymer or (co)polymers (B) are chosen from:poly(diallyldimethylammonium chloride);poly(acryloxyethyltrimethylammonium chloride); copolymers based ondiallyldimethylammonium chloride or on acryloxyethyltrimethylammoniumchloride; styrene-maleic anhydride copolymers which are imidized andquaternized by an alkyl chloride or benzyl chloride or by an acid;poly(acrylamidopropylpropyltrimethylammonium chloride); polyacrylamide;poly(vinyl alcohol); and poly(ethylene oxide).
 7. The dispersion asclaimed in claim 6, characterized in that the dispersing (co)polymer or(co)polymers are chosen from: cationic polymers based on styrene, onacryloxyethyltrimethylammonium chloride and on polyethoxy methacrylate,with or without a hydrophobic group, the latter being either thetriphenylstyryl group or an alkyl chain; amphoteric polymers based onstyrene, on acryloxyethyltrimethylammonium chloride, on methacrylic acidand on polyethoxy methacrylate, with or without a hydrophobic group, thelatter being either the triphenylstyryl group or an alkyl chain;cationic polymers based on styrene, on diallyldimethylammonium chlorideand on polyethoxy methacrylate, with or without a hydrophobic group, thelatter being either the triphenylstyryl group or an alkyl chain;cationic polymers based on styrene, on acryloxyethyltrimethylammoniumchloride and on alkyl (meth) acrylate comprising a long C₁₂-C₃₀ chain,the polyethoxy methacrylate with a triphenylstyryl group beingrepresented by the formula (VTI):

with r an integer from 1 to
 60. 8. The dispersion as claimed in one ofclaims 1 to 7, characterized in that the salt or salts (C) are chosenfrom ammonium sulfate, sodium sulfate, aluminum sulfate, sodiumchloride, sodium dihydrogenphosphate and sodium hydrogenphosphate, itbeing possible for these kosmotropic salts to be combined with achaotropic salt, such as sodium thiocyanate or ammonium thiocyanate. 9.A process for the manufacture of the aqueous dispersion as defined inone of claims 1 to 8, characterized in that the radical polymerizationin a saline aqueous medium of the monomer or monomers (1) to (6) asdefined in either of claims 1 and 2 is carried out in the presence of atleast one polymer dispersant (B) as defined in claim 3 and of at leastone inorganic salt (C) as defined in claim
 3. 10. The process as claimedin claim 10, characterized in that the aqueous dispersion is prepared byusing: from 10 to 50 parts by weight of the composition of thewater-soluble monomers (1) to (6); from 0.5 to 25 parts by weight of thepolymer dispersant or dispersants (B); and from 10 to 45 parts by weightof the salt or salts (C), these parts being with respect to 100 parts byweight of the reaction mixture composed of water, the dispersing polymeror polymers (B), the salt or salts (C) and the composition of themonomers (1) to (6).
 11. The process as claimed in claim 10,characterized in that the aqueous dispersion is prepared by using: from15 to 30 parts by weight of the composition of the water-solublemonomers (1) to (6); from 1 to 10 parts by weight of the polymerdispersant or dispersants (B); and from 21.5 to 34 parts by weight ofthe salt or salts (C), these parts being with respect to 100 parts byweight of the reaction mixture composed of water, the dispersing polymeror polymers (B), the salt or salts (C) and the composition of themonomers (1) to (6).
 12. The process as claimed in one of claims 9 to11, characterized in that it is carried out at a temperature of −40° C.to 160° C.
 13. The process as claimed in claim 12, characterized in thatit is carried out at a temperature of 30 to 95° C.
 14. The use of thedispersion of water-soluble copolymers as defined in one of claims 1 to8 or prepared by the process as defined in one of claims 9 to 13, asflocculating agent for the treatment of waste water; dehydrating agent;agent for retaining fibers and fillers in processes for the manufactureof paper; agent facilitating the cleaning of supports, such as textiles;agent for dispersing fillers; inhibiting agent for the transfer ofpigments and dyes onto various supports, such as textile; and thickener.